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This work attempts to relate global teleconnections, through physical phenomena such as the El Nino-Southern Oscillation (ENSO), Artic Oscillation (AO), North Atlantic Oscillation (NAO), and the Pacific North American (PNA) pattern to synoptic-scale weather patterns and precipitation in the Roanoke, Virginia region. The first chapter describes the behavior of the El Nino-Southern Oscillation (ENSO) by implementing non-homogeneous and homogeneous Markov Chain models on a monthly time series of the Troup Southern Oscillation Index (SOI), a sea level pressure based index. Meanwhile, in the second chapter the author has related or an attempt has been made to relate global teleconnections (through ENSO and AO) to a synoptic scale, station-centered set of weather types in order to assess trends in precipitation. The final portion of this work describes spatial variability of seasonal precipitation in southwestern Virginia in a context that incorporates global teleconnections (through AO, PNA, NAO, and ENSO) and frontogenesis. It was found that the Markov property can be used to describe and predict the monthly evolution of ENSO. Also evident is an increased probability of a wetter spring in the Roanoke region when El Nino combines with the negative phase of the AO during the previous winter. Meanwhile, Roanoke winters subsequent to a fall season described by this same El Nino-AO condition are predicted to receive more precipitation than average. This work additionally showed possible trends between frontal-precipitation events in the Roanoke region and global teleconnections. / Master of Science

Teleconnections between ENSO events and growing-season precipitation variations on the Canadian Prairies are examined. Correlation and composite analyses indicate that between 1948 and 1991, El Nino events were associated with more frequent extended dry spells. Conversely, La Nina events coincided with fewer extended dry spells. Both relationships occurred during the third growing season following the onset of the ENSO events (i.e. approximately a 10-season or 30-month lag). A series of atmosphere - ocean teleconnections over the Pacific Ocean including Pacific North America (PNA) circulation patterns, North Pacific sea-surface temperature anomalies and upper-atmospheric circulation anomalies were found to result in growing-season precipitation variations over the Canadian Prairies. Results of this analysis are incorporated into a conceptual model which may form the basis of a long-range forecasting technique of growing-season precipitation variations on the Canadian Prairies.

Galactic cosmic rays are the high-energy particles that stream into our solar system from distant corners of our Galaxy. The Earth's atmosphere serves as an ideal detector for the high energy cosmic rays which interact with the air molecule nuclei causing propagation of extensive air showers. The primary cosmic ray particles interact with the molecules in the atmosphere and produce showers of secondary particles (mainly pions) at about 15 km altitude. These pions decay into muons which are the dominant particles of radiation (about 80%) at the surface of the Earth. In recent years, there are growing interests in the applications of the cosmic ray measurements such as space/earth weather monitoring, homeland security activities based on the cosmic ray muon tomography, radiation effects on health via air travel, etc. A simulation program (based on the Geant4 software package developed at CERN) has been developed at Georgia State University for studying cosmic ray showers in the atmosphere. The results of this simulation study will provide unprecedented knowledge of geo-position-dependent cosmic ray shower profiles and will significantly advance cosmic ray applications. Simulation results are critically important for determining the temperature coefficients in every pressure layer in the atmosphere in order to calculate the temperature variations using the cosmic ray data. Using a single particle shower simulation, the weighted particle altitude distributions on a global scale are calculated with geomagnetic field implementation. The results of the simulation can aid the computation of the effective temperature in stratosphere.

Corn production in the United States has become increasingly efficient over the years. The use of nitrogen fertilizers has played a substantial role in this efficiency. Nitrogen drives biomass production which leads to increased yields. Unlike other nutrients, nitrogen is more mobile making it easier to lose through leaching and volatilization. The first part of this analysis uses an econometric model to examine the relationship between nitrogen usage and weather data. This relationship leads to farm management decisions to reduce nitrogen fertilization expenses. In addition to the use of nitrogen fertilizers, farmers in Kentucky take advantage of an abundance of poultry litter as a fertilizer source. Traditional poultry litter fertilization methods are being challenged by new technology, sub-surface injection, which has the potential to increase corn yields as compared to other methods. The second part of this analysis uses a resource allocation linear programming model to determine the economic viability of the sub-surface injection method for both spring and fall fertilizer applications. This model also reveals both farm management implications and provides valuable information for the development and commercialization of the sub-surface injector.

<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>

<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>

Magister Educationis - MEd (Mathematics and Science Education) / This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called ‘mixed methods’) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study. The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin’s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997). Further analyses were conducted on learners’ beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement). After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science–IK curriculum for the Natural Sciences subjects in South African schools.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The Western Cape has been subject to extreme rainfall storms in the last decade, which has been responsible for millions of Rands worth of damage to public infrastructure and human settlements. Current climate model projections under climate change suggest that the Western Cape can expect greater rainfall intensities, with magnitude of rainfall events increasing, but the frequency of occurrence of events decreasing. The aim of this research is to assess if historical short duration rainfall data provides any evidence to support increasing intensities in rainfall in the Western Cape. Short duration rainfall data (< 24 hours), consisting of digitised autographic- and automatic weather station data (AWS), was selected from the South African Weather Services’ database for the Western Cape and wider South African region, in order to combine the data for an extension of the effective record length. Numerous difficulties were encountered with the data that required the application of editing and quality control procedures. The digitised autographic data contained many errors and generally compared poorly to standard gauge daily rainfall totals of the same period. After the application of editing and quality control procedures, seven stations were selected and their autographic and AWS data was combined for further detailed analysis. Analysis was divided into two sections, one for the analysis of the magnitude of the rainfall, the other for the frequency of occurrence of rainfall events. For the magnitude analysis, nonstationary extreme value theory was applied by implementing a parametric and non-parametric non-stationary approach to both the generalised extreme value distribution (GEV) with an annual maximum series, and a generalised Pareto distribution with a peaks over threshold series. The parametric approach entailed fitting linear models to the parameters of the extreme value distributions, and the non-parametric approach tested if return levels of the distributions remained constant over a moving window period. The frequency analysis entailed the recording of the annual number of rainfall events exceeding predetermined threshold values. For the magnitude analysis, the parametric approach only produced two stations with significant non-stationarity and only for the GEV, whilst the non-stationary approach produced results that can indicate non-parametric behaviour, but this was most likely because of the combination of autographic and AWS data. The frequency analysis produced results that indicated no observable results for some stations, while others produced trends that are consistent with a change from the autographic to AWS data. This lead to the conclusion that with the available data, no clear or significant evidence supporting increasing intensities or any other change in short duration rainfall was found regarding the magnitude and frequency of occurrence of rainfall events. / AFRIKAANSE OPSOMMING: The Wes-Kaap het die afgelope dekade deur uiterse storms deurgeloop wat miljone Rande se skade aan publieke infrastruktuur en nedersettings veroorsaak het. Huidige klimaatsmodel resultate wat klimaatsverandering inkorporeer, beraam dat die Wes-Kaap hoër reënvalintensiteite kan verwag, waar die grootte van die en reënvalgebeurtenisse toeneem, maar die frekwensie van die reënvalgebeurtenisse afneem. Die doel van hierdie navorsing is om te bepaal of historiese kortduurtereënvaldata in die Wes-Kaap enige toenemende reënvalintensiteite aandui. Kortduurtereënvaldata (< 24 uur) wat uit versyferde autografiese- en automatiese weerstasie (AWS) data bestaan, was uit die Suid Afrikaanse Weerdienste se databasis gekies vir stasies in dieWes-Kaap en die wyer Suid Afrikaanse gebied, sodoende om die effektiewe rekordlengte te verleng. Redigering- en kwaliteitsbeheerprosudures moes toegepas word na ’n aantal probleme met die data ontdek was. Die versyferde autografiese data het baie foute bevat en oor die algemeen swak vergelyk met die standaard daaglikse totaalmetings van dieselfde periode. Na die redigering- en kwaliteitsbeheerprosudures toegepas was, was sewe stasies gekies en hul autografiese en AWS data was saamgestel vir verdere analise. Die analise het uit twee afdelings bestaan: die analise van die grootte van die reënvalgebeurtenisse, en die frekwensie van die reënvalgebeurtenisse. Nie-stasionêre ekstreemwaardeteorie was toegepas op die grootte van die reënvalgebeurtenisse deur gebruik te maak van parametriese en nie-parametriese nie-stasionêre metodiek. Die veralgemeende ekstreemwaardeverdeling (AEW) met ’n jaarlikse maksimum reeks, en die veralgemeende Paretoverdeling met ’n pieke bo drempelwaarde reeks was gebruik. Die parametriese metode het bestaan uit die passing van lineêre modelle aan die parameters van die estreemwaardeverdelings. Die nie-parametriese metode het getoets of die terugkeervlakke van die verdelings konstant gebly het oor ’n bewegende vensterperiode. The frekwensie analise het bestaan uit die aantekening van die jaarlikse reënvalgebeurtenisse wat bepaalde drempelwaardes oorskry. Die parametriese metode het net twee beduidende nie-stasionêre staties opgelewer, uitsluitlik vir die AEW. Die nie-parametriese metode het resultate gegenereer wat moontlike niestasionarieit aandui, maar dit is heel moontlik as gevolg van die samestelling van die autografiesen AWS data. Die frekwensie analise het óf geen sigbare neiging vir die resultate vir ván stasies gegenereer nie, óf het resultate gegenereer wat aandui op die samestelling van die autografiesen AWS data. Dit het tot die gevolgtrekking gelei dat daar geen aanduiding in die kortduurtereënvaldata bestaan wat toenemende reënvalintensiteite ondersteun nie vir beide die grootte en frekwensie van reënvalgebeurtenisse.

Background: Vietnam suffers consequences of global warming. There is limited data of the relationship between weather, extreme heat and potential mental health problems. It is therefore crucial to study heat-related mental illnesses and to establish good solutions with relevant adaptations to global warming. The adaptation measures should give attention to people that live in areas facing annual extreme weather, and protecting health in general and more specifically mental health of citizens. The study aimed to examine relationships between weather patterns, extreme heat or heatwaves, and mental disorders, and to investigate factors contributing to increased vulnerability and susceptibility. Methods: The thesis includes a systematic review and a hospital-based study using data from the Hanoi Mental Hospital for five years (2008 – 2012), with mental disorders diagnosed by ICD10 (F00-99) to estimate the effects of weather variation, seasonality, increased temperatures, and heatwaves on hospital admissions for depression and other mental disorders. A negative binomial regression model accounting for yearly study period, time trends, and day of the week was used to analyze the relationship between seasonality, heatwaves, and monthly and daily mental disorder hospitalizations. Results: Our findings showed (i) a general tendency for more admissions between May and December, with a seasonal bi-annual high between May-June and November-December, and elevated ambient temperature was significantly related to increasing admissions for depressive disorders; (ii) the number of hospital cases for mental disorders increased in the summer seasone specially in June, and two percent of cases emerged during elevated temperature of one degree Celsius; and (iii) when compared with non-heatwave periods, heatwaves amounted to increasing risks for admission for the whole group of mental disorders (F00-79), and admissions for mental disorders among residents in rural communities and in the elderly population increased significantly during heatwaves. Conclusion: There were associations between hospital admissions for depression and other mental disorders and seasonality, weather patterns, elevated temperatures, and heatwaves. The associations grew stronger with the length of the heatwaves and particularly the elderly appeared more sensitive to seasonality, hot weather and heatwaves.